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Effectiveness and Safety of Tolvaptan for the Management of Hyponatremia: Risk of Inadvertent Overcorrection
J. Kor. Soc. Health-syst. Pharm. 2018;35:430-440
Published online November 30, 2018;
© 2018 Korean Society of Health-System Pharmacists

Mi Seon Parka,b, Seung Yong Parkb,c, Seoung Ju Parkb,c, Jin Seon Beoma,b, Hyo Cho Ahna, Ju Sin Kima,† and Heung Bum Leec,†

Department of Pharmacy, Chonbuk National University Hospitala
20, Geonjiro, Deokjin-gu, Jeonju-si, Jeollabuk-do, 54907, Republic of Korea Chonbuk National University Hospital Regional Pharmacovigilance Centerb, Department of Internal Medicine, Chonbuk National University Hospitalc
Correspondence to: Heung Bum Lee, Tel:063-250-1685,
Ju Sin Kim, Tel:063-250-1005,
Received February 9, 2018; Revised March 26, 2018; Accepted September 14, 2018.
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Background : Hyponatremia is the most common electrolyte disturbance in hospitalized patients and has been associated with increased morbidity and mortality. Tolvaptan, a vasopressin receptor antagonist, is increasingly used for the treatment of euvolemic and hypervolemic hyponatremia. The aim of this study was to evaluate the effectiveness and safety of tolvaptan for the management of hyponatremia.
Methods : This study was a retrospective evaluation of 106 patients who received at least one dose of tolvaptan for hyponatremia at a single tertiary academic hospital between January 2014 and June 2015. The primary endpoint was the change in serum sodium concentration after tolvaptan administration within 24 hours, with secondary endpoints of overcorrection and adverse effects.
Results : The mean initial dose of tolvaptan was 20.2±7.2 mg and the median duration of treatment was 15 days (range, 1-261 days). The maximal changes in sodium levels at 24 and 48 hours were 8.2± 4.7 mmol/L and 10.5±15.3 mmol/L, respectively. Of 99 patients in whom sodium concentrations were followed up, sodium overcorrection was observed in 26 (26.3%) patients, which was associated with concomitant use of an enzyme inhibitor (odds ratio [OR] = 4.80, 95% Cl: 1.27-18.15). However, sex, body mass index (BMI), serum albumin, a daily dose of tolvaptan, and concomitant use of hypertonic saline did not show any significant difference in overcorrection. The most commonly reported adverse effects were mild and related to aquaresis, such as polyuria, thirst, and constipation. However, severe adverse effects such as hyperkalemia, hypotension, and one death related to osmotic demyelination were also reported.
Conclusions : Tolvaptan is effective for treating hyponatremia. Nevertheless, the drug should be used cautiously due to serious adverse effects related to sodium overcorrection.
Keywords : Tolvaptan, Hyponatremia, ADR (Adverse Drug Reaction), Overcorrection

November 2018, 35 (4)